Mike Maca leaned forward in the federal courtroom Friday as the man accused of killing his brother in an arson fire on Chicago’s Southwest Side nearly two years ago waited to learn his fate.

When the word “guilty” was read aloud, Maca clutched a fist over his mouth and let out several stifled sobs, while his sister and niece wiped away tears of their own. Across the courtroom, Juan Adame, sat expressionless at word of his conviction, scribbling notes on a sheet of paper.

After a weeklong trial, a jury deliberated a little more than an hour before convicting Adame, 39, of setting fire to his girlfriend’s apartment building in January 2012 in a jealous rage after she broke off their rocky relationship.

The girlfriend wasn’t home at the time, but James Maca, a neighborhood fixture who lived in an adjacent apartment, was trapped by the flames and died of smoke inhalation and carbon monoxide poisoning.

Adame, who has been in custody since his arrest two months after the arson, faces up to life in prison at sentencing on Feb. 11.

“I want him to sit and think about what he’s done for the rest of his life,” Mike Maca said Friday outside U.S. District Judge Harry Leinenweber’s courtroom. “

Adame’s attorney, Frank Avila, vowed an appeal, saying the judge had erred in letting an arson victim on the jury. In closing arguments earlier Friday, he told jurors that prosecutors had no direct evidence linking Adame to the arson and that police failed to follow up on other promising leads.

“There’s no fingerprint on the gas can, no footprint leaving the place, nothing,” Avila told jurors.

In her testimony at trial, Adame’s former girlfriend, Blanca Ortiz, painted him as odd and controlling. Prosecutors presented evidence that during their six-month relationship, Adame had broken into her home in the 4200 block of West 63rd Street on several occasions and taken her personal possessions – a Marilyn Monroe blanket, photographs, even her Barbie dolls. He also had filmed Ortiz without her knowledge, she said.

Ortiz testified that hours before the fatal blaze, she and Adame had fought about her decision to return to work as an exotic dancer. Later that night, she came home to find her car and television missing and broke up with him by text message. “I’m not forgiving u this time,” she said in one text shown to jurors.

Another former girlfriend of Adame’s testified she was with him early that morning when he stopped at a gas station. Prosecutors said Adame left the girl waiting around the corner while he went into Ortiz’s apartment, doused the bedroom and couch with gas and set them ablaze.

Maca, 60, known affectionately in the West Lawn neighborhood as “Boots,” was seen waving frantically from his second-floor window. His friends told the Tribune he may have become trapped after going back for his beloved cats.

Maca’s family said he was a courteous, big-hearted person who loved his Bears and had no enemies.

“My brother was the most charismatic man you’d ever want to meet,” his sister, Donna Kluppelberg, said outside court. “God sent him the justice he deserved.”